From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A3591C26 for ; Wed, 23 Nov 2022 09:03:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7681C433C1; Wed, 23 Nov 2022 09:03:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669194233; bh=5HbzkVatp0g3AbejAztJgq1G/krFE8J0n5HgUG76pPA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yNFb14HEch9tTtwYyNTOlm1MOzayFt3nFPIhwLInTvS84cNMyXDVBflRoaBB2tGLw /uFkswYrCSyCmeVWPxO7ziUkvfcQk2sUtCi8MWO2zG7gLeDZMGlqEcjq56P2mMk0f4 M6Fb69AR7YANdvKzlGlwitNYkQz4aHMu1znCBLXw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jisheng Zhang , Guo Ren , Palmer Dabbelt , Sasha Levin Subject: [PATCH 4.19 021/114] riscv: process: fix kernel info leakage Date: Wed, 23 Nov 2022 09:50:08 +0100 Message-Id: <20221123084552.689702260@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084551.864610302@linuxfoundation.org> References: <20221123084551.864610302@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jisheng Zhang [ Upstream commit 6510c78490c490a6636e48b61eeaa6fb65981f4b ] thread_struct's s[12] may contain random kernel memory content, which may be finally leaked to userspace. This is a security hole. Fix it by clearing the s[12] array in thread_struct when fork. As for kthread case, it's better to clear the s[12] array as well. Fixes: 7db91e57a0ac ("RISC-V: Task implementation") Signed-off-by: Jisheng Zhang Tested-by: Guo Ren Link: https://lore.kernel.org/r/20221029113450.4027-1-jszhang@kernel.org Reviewed-by: Guo Ren Link: https://lore.kernel.org/r/CAJF2gTSdVyAaM12T%2B7kXAdRPGS4VyuO08X1c7paE-n4Fr8OtRA@mail.gmail.com/ Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- arch/riscv/kernel/process.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index d7c6ca7c95ae..64180108072c 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -104,6 +104,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, { struct pt_regs *childregs = task_pt_regs(p); + memset(&p->thread.s, 0, sizeof(p->thread.s)); + /* p->thread holds context to be restored by __switch_to() */ if (unlikely(p->flags & PF_KTHREAD)) { /* Kernel thread */ -- 2.35.1